High Dynamic Range and How You Can Use It

Hi All,

Today I took a trip to the Hopewell Culture National Historical Park (Mound City) in Chillicothe, Ohio to take some high dynamic range (HDR) digital photographs. Before getting too deep into the post I just want to say get out and visit our National Parks. The rangers at Mound City were very knowledgable, friendly, and willing to answer questions.

Brief technical interlude...I took three exposures using a Nikon D70s camera, and used the merge to HDR feature in Adobe Photoshop CS4 to do these images. Before I get any hate mail, I know there are better programs for HDR image processing but I wanted to use the Photoshop method.

The work flow:

1. Merge RAW files to HDR from Adobe Bridge
2. Convert to 16 bit and make adjustments using the HDR conversion dialog. I use the "Local Adaptation" method. Because I want the images to look like what my eyes saw, I used low radius and threshold settings - careful not to make the image look too fantasy driven.
3. Save as a tiff file.
4. Open the tiff in Adobe Camera Raw and make adjustments as needed
5. Finally, I save as a PSD file so I can do adjustments in Photoshop like sharpening and other stuff. I keep the tiff file as a "working" copy of the HDR image (almost like a digital negative).

This workflow works for me...you have many options here so play around.

Now to the reason for the post - How can you (an artist - painter) use HDR images?

I admit, working from photographs is not as good as from life. Our eyes see approximately 14 exposure values were the camera only "sees" one. With HDR you can take several exposures and merge them into one creating a simulated range of tones closer to what you see with your own eyes.

If we (artists) want to work from photographs for reference then why not take advantage of HDR? I beleive technology can help us here. The HDR photographs can be part of your refernce tools. Consider this, you plan to paint a landscpe and visit the location. You take a range of pictures to create an HDR image to use as your composition. You take notes, make a quick sketch, a small color study, and there you go; a great collection of reference material to use back in the studio.

For the travelers out there...it is easier to pack a camera, pencils, watercolors, and notebooks than to try to get on the airplane with tubes of oil paints, and thinner (which is not allowed). Do you really want to throw out 13 or so tubes of oil paint just to travel by airplane? I don't! Of course, if you are driving then try the en plein air in oils route if you can (an I recommend it).

Here are a few HDR and non-HDR images from the visit...

HDR Version:

Non-HDR version...

HDR Version:

Non-HDR version...

HDR Version:

Non-HDR version...

Please keep in mind the HDR images I created for this post are three exposures only. Very little editing was done so that I could post this quickly. If you take a little more time to process and edit the images and use more exposures you may get even better results. I think HDR is a great way to capture images closer to what we see. You do need a tripod, and avoid windy days. Portraits of people are not good for HDR...use off camera flash for that...you can get good results that way (that is another post).

Finally, I'll say it again...Go out and enjoy the National Parks! You can learn, and get out of the studio.

- Michael